论文标题
在大规模损坏的费米 - 哈伯德模型中可调传输
Tunable transport in the mass-imbalanced Fermi-Hubbard model
论文作者
论文摘要
量子多体系统的后期动力学以不同的动力普遍性类别组织，其特征在于其保护定律，因此以它们的新兴流体动力运输为特征。在这里，我们研究了具有不同质量的两种费米子种类的一维哈伯德模型中的运输。为此，我们开发了一种在弱相互作用的极限中有效的量子玻尔兹曼方法。我们探索了从弹道到扩散运输的交叉，其时间表在很大程度上取决于这两个物种的质量比。对于可与矩阵产品运营商访问的时间尺度，我们在这些数值确切的结果与量子玻尔兹曼方程之间发现了极好的一致性，即使对于中间相互作用也是如此。我们研究了两种情况，这些情况最近已通过超电原子实验进行了研究。首先，在倾斜的情况下，量子玻尔兹曼方程预测，运输会显着减慢并变得宽敞，与以前的研究一致。其次，我们研究了通过取代谐波限制潜力的探测运输，并与最新的实验数据找到良好的定量一致性[N. Darkwah Oppong等人，Arxiv：2011.12411]。我们的结果表明，量子玻尔兹曼方程是研究不均匀电位中复杂的非平衡状态的有用工具，因为通常用合成量子系统探测的是。
The late-time dynamics of quantum many-body systems is organized in distinct dynamical universality classes, characterized by their conservation laws and thus by their emergent hydrodynamic transport. Here, we study transport in the one-dimensional Hubbard model with different masses of the two fermionic species. To this end, we develop a quantum Boltzmann approach valid in the limit of weak interactions. We explore the crossover from ballistic to diffusive transport, whose timescale strongly depends on the mass ratio of the two species. For timescales accessible with matrix product operators, we find excellent agreement between these numerically exact results and the quantum Boltzmann equation, even for intermediate interactions. We investigate two scenarios which have been recently studied with ultracold atom experiments. First, in the presence of a tilt, the quantum Boltzmann equation predicts that transport is significantly slowed down and becomes subdiffusive, consistent with previous studies. Second, we study transport probed by displacing a harmonic confinement potential and find good quantitative agreement with recent experimental data [N. Darkwah Oppong et al., arXiv:2011.12411]. Our results demonstrate that the quantum Boltzmann equation is a useful tool to study complex non-equilibrium states in inhomogeneous potentials, as often probed with synthetic quantum systems.
